文献类型：期刊文献

英文题名：Ga-Doped and Pt-Loaded Porous TiO2-SiO2 for Photocatalytic Nonoxidative Coupling of Methane

作者：Wu, Shiqun[1,2];Tan, Xianjun[5];Lei, Juying[1,2];Chen, Haijun[3,4];Wang, Lingzhi[1,2];Zhang, Jinlong[1,2]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Key Lab Adv Mat, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem & Mol Engn, Inst Fine Chem, 130 Meilong Rd, Shanghai 200237, Peoples R China;[3]Nankai Univ, Dept Elect, Tianjin 300071, Peoples R China;[4]Nankai Univ, Tianjin Key Lab Photoelect Thin Film Device & Tec, Tianjin 300071, Peoples R China;[5]Chinese Acad Sci, Shanghai Adv Res Inst, Key Lab Low Carbon Convers Sci & Engn, Shanghai 201210, Peoples R China

年份：2019

卷号：141

期号：16

起止页码：6592

外文期刊名：JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

收录：;EI(收录号：20191606804980);WOS:【SCI-EXPANDED(收录号:WOS:000466053400024)】；

基金：This work was supported by the National Natural Science Foundation of China (21673073, 21677048, and 5171101651), the Science and Technology Commission of Shanghai Municipality (18520710200, 16JC1401400, and 17520711500), Shanghai Pujiang Program (18PJD012), the PetroChina Innovation Foundation (2015D-5006-0402), and the Fundamental Research Funds for the Central Universities (222201717003 and 22221818014).

语种：英文

外文关键词：Density functional theory - Silica - Gallium compounds - Hydrogen production - Structural design - Platinum - Titanium - Calculations - Chemical analysis

摘要：Photodriven nonoxidative coupling of CH4 (NOCM) is a potential alternative approach to clean hydrogen and hydrocarbon production. Herein, a Mott-Schottky photocatalyst for NOCM is fabricated by loading Pt nanoclusters on a Ga-doped hierarchical porous TiO2-SiO2 microarray with an anatase framework, which exhibits a CH4 conversion rate of 3.48 mu mol g(-1) h(-1) with 90% selectivity toward C2H6. This activity is 13 times higher than those from microarrays without Pt and Ga. Moreover, a continuous H-2 production (36 mu mol g(-1)) with a high CH4 conversion rate of similar to 28% can be achieved through a longtime irradiation (32 h). The influence of Ga on the chemical state of a surface oxygen vacancy (Vo) and deposited Pt is investigated through a combination of experimental analysis and first-principles density functional theory calculations. Ga substitutes for the five-coordinated Ti next to Vo, which tends to stabilize the single-electron trapped Vo and reduce the electron transfer from Vo to the adsorbed Pt, resulting in the formation of a higher amount of cationic Pt. The cationic Pt and electron-enriched metallic Pt form a cationic-anionic active pair, which is more efficient for the dissociation of C-H bonds. However, the presence of too much cationic Pt results in more C2+ product with a decrease in the CH4 conversion rate due to the reduced charge-carrier separation efficiency. This study provides deep insight into the effect of the doping/loading strategy on the photocatalytic NOCM reaction and is expected to shed substantial light on future structural design and modulation.